Mixing of liquids, liquids and solids and solids and solids is routinely achieved by either using a stirring device or a by shaking or rotating the container; in the first instance, a risk of contamination is inherent and in the other, the cost of large mechanical devices required to produce a motion. Niazi inventions take novel approach to mixing without any external stirring device inserted into a mixing vessel:
a. mechanical or magnetic levitation of container shaken in linear, vertical or orbital motion, low energy operation.
b. mixing in flexible bags by compressing an edge to create an internal wave, instead of shaking the container.
c. geometric dilution using closed containers wherein mixing occurs under gravitation flow provides a protected environment without the need for larger containers to quality for CFR 21:210 single batch cGMP qualification.
While several applications are illustrated in the bioprocess industry, the devices and methods are equally application to any industry where a protected mixing is preferred. Additional applications pending.
Stationary bioreactors and mixing vessels fitted with flexible bags utilize wave hydrodynamic principle wherein a movable flap repeatedly compresses one or multiple edges of the bag to create a wave motion to induce mixing. The technology is applicable every type of biological process and products, as well as in the chemical industry.. By keeping the container stationary, it is now possible to use flexible bags, which are otherwise fragile, for any size container and achieve optimal mixing at a very low cost and keep the content protected since no stirring is introduced from outside. PDF
Levitation is widely used in many industries; here a physical levitation by hanging in the air or by magnetic levitation, creating a zero gravity, allows use of small force to shake the container in vertical, horizontal (linear or orbital) direction and mix the content without the need to introduce an external stirring device. PDF.
The CFR 21 Part 210 defines a batch as "a specific quantity of a drug or other material that is intended to have uniform character and quality, within specified limits, and is produced according to a single manufacturing order during the same cycle of manufacture." Many industries face the challenge of batch size and it is preferred to pool several containers to have "uniform character" to qualify as a single batch. A traditional option will be to mix the content in a larger container, but that defeats the utility of smaller containers. A method of mixing contents of several containers using a common container that receives a fixed fraction from each container and returns it allow keeping the content in several containers, yet qualify them collectively as a single batch. Applied here to upstream processing, the technology readily adaptable to any industry. PDF